Ionode IJ pH V5.1 - Manual (Page 21)

Ionode IJ Instruction Manual 21
4.4.1. Cleaning
As pH and ORP are surface based
measurements, the cleanliness of the sensor
and
junction is critical for accurate
measurement. For new electrodes, drift, poor
slope and long response times are often due to
an unclean sensor and/or junction.
Clean the electrode periodically depending on
the application.
Remove the sleeve (see 3 . Preparation ). Clean
the membrane, ground glass stem and sleeve
with solvents, detergents, or acid. DO NOT
USE ABRASIVE MATERIALS!
a) Alkaline samples and scale: soak the
membrane in approximately 1M HCl for an
hour. Wash well with tap water and soak
before use.
b) Grease and oil: wipe the membrane and
ground stem with cotton or tissue soaked in
acetone followed by methylated spirits.
Wash with deionised water and soak before
use.
c) Solids and organics: wipe the membrane
and junction with cotton or tissue soaked in
a mild non-alkaline detergent (e.g. Palmolive
™). Wash with deionised water and soak
before use.
d) Strongly absorbed impurities and chemically
bonded substances such as silicones can be
removed with non-
abrasive Jif ™ detergent.
This removes a fine layer of contaminated
pH glass without damaging the membrane.
Jif ™ can also be used for routine cleaning
(e.g. every three months)
. Use Jif ™
undiluted on a soft cloth and scrub the
membrane well. Wash well and soak.
e) Protein contamination: soak the membrane
in 1% pepsin in 0.1M HCl for 15 minutes
followed by rinsing with deionised water, and
soak in 20% KCl before use.